%0 Journal Article %A Daboussi-Bareyre, M.-J. %T Heterokaryosis in Nectria haematococca: Complementation Between Mutants Affecting the Expression of Two Differentiated States %D 1980 %J Microbiology, %V 116 %N 2 %P 425-433 %@ 1465-2080 %R https://doi.org/10.1099/00221287-116-2-425 %I Microbiology Society, %X Certain mycelia of the ascomycete Nectria haematococca show two morphological differentiated states, rings and sectors, which are cytoplasmically transmissible. Two nuclear loci A and S, appear to be involved in the control of these differentiated states. Mutations in the A region either prevent ring formation and the synthesis of the corresponding infectious factor (type a) or modify ring expression (type 58). Using forced heterokaryons, it was demonstrated that locus A corresponds to a single gene which exists in three allelic forms, wild-type, a and 58. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-116-2-425